高水压条件下盾构隧道联络通道及集水井施工力学行为研究

以武汉地铁越长江盾构隧道江中段联络通道及集水井为依托,提出一种适合砂性地层高水压条件下地下结构施工力学行为数值模拟的计算处理方法。即耦合使用地层-结构法和荷载-结构法,对土体和水体进行分别处理。其中,地层依据地层-结构法按实际地层建模,容重采用干容重;水体则作为荷载直接施加在结构表面,水体所产生荷载根据施工过程施加;结构未修建之前按水压施加在底部透水性较差基岩上进行地层初始应力场计算。将上述方法应用于武汉地铁越长江盾构隧道联络通道及集水井施工力学行为数值模拟中,得出影响钢管片、联络通道衬砌和集水井衬砌变形及应力分布的关键因素;验证提出的适合砂性地层高水压计算处理方法的可行性,并提出针对性建议。

Construction Mechanics Behavior of Interconnecting Aisle and Sump Pit of Shield Tunnel under High Hydraulic Pressure

Taking the interconnecting aisles and sump pit of the Wuhan Metro shield tunnel across the Yangtze River as the engineering background,numerical simulation of the construction mechanics behavior of the underground structures in sandy strata under high hydraulic pressure was dealt with.The core ideas are as follows: The stratum-structure method and the load-structure method are coupled in calculation,the soil mass and the mass of water are treated respectively;the strata are modeled with the stratum-structure method and the dry bulking figure is used as the parameter of soil;the mass of water is directly loading onto the surface of the structures and its application is decided on specific conditions of construction and is implemented step by step;before the structures are built,the initial stress field of the stratum is calculated just as the hydraulic pressure is applied to the upper surface of the bedrock which has low permeability.By using the above method,the key factors affecting the deformation and stress distribution of steel segments,interconnecting aisles and sump pits are found.Calculation applicable to sandy strata under high hydraulic pressure is verified.Suggestions are made in accordance.